BIG piston deck clearance issue

So I began to clean the second hand 383 that I bought to do a cheap rebuild on and put in my truck. I began cleaning the pistons and numbering them and when I got to the second to last piston I found that it sits WELL above 0 deck. The deck seems level and every other piston is perfectly at 0 deck. Anyone know what could cause this or what to do? I'm thinking maybe just replace that piston and rod.

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